Up till OS X 10.9 Mavericks, previous incarnations of OS X could unofficially support TRIM but things changed since Mavericks, where Apple introduced KEXT signing as a purported means ‘to increase the security of OS X’.

Since then and until yesterday, it became almost impossible to engage OS X side TRIM support without encountering major issues resulting from this new KEXT signing feature.

Even if a user managed to engage OS X TRIM support, an OS X update, followed by a restart usually lands the user with a Mac that simply refuses to boot.

Notwithstanding KEXT signing, another arguable reason users were denied access to OS X TRIM support was to limit support for only Apple approved Solid State Drives (SSD) hard drives.

The great news is that Apple has once again released the built in OS X TRIM feature in OS X Yosemite 10.10.4.

A note of caution however, the TRIM activation process we are about to share is an unofficial and unadvertised feature of OS X 10.10.4 so, just like how Apple has encoded a warning message, we echo the same, “proceed at your own risk”.